tangent – podictionary 609
Now it’s amazing how complicated people are. You think you know them and suddenly you realize that there is a whole other side to them that you never even realized existed. Here I am looking at a website that I wasn’t expecting. Let me read you what it says:
Britney’s Guide to Semiconductor Physics: It is a little known fact, that Britney Spears is an expert in semiconductor physics. Not content with just singing and acting, in the following pages, she will guide you in the fundamentals of the vital laser components that have made it possible to hear her super music in a digital format.
Who’d a thunk it? I’ll include a link to that site on the podictionary blog.
Now you may think I’m going off on a tangent here and that Britney Spears has very little to do with etymology. And of course you are right, but I’m doing it for a reason. When someone goes off on a tangent—and I do it all the time—they are invoking a word that comes from math.
You know of course what a tangent is in math. Actually it’s a couple of things.
In geometry a tangent is a straight line that touches another line, often a circle, in just one place. The reason this is called a tangent is that in Latin the word tangere meant “to touch” and that’s what the line does, it just touches the circle.
In trigonometry there’s also a tangent. While this kind of tangent seems more complicated it really isn’t. The word trigonometry also comes from Latin of course and it literally means “triangle measurement”, so once you know that, trigonometric tangents can be a snap. Think of that geometric tangent touching the circle (A). If you draw a line from the place it touches the circle, to the middle of the circle (A, O), then you’ll have two lines that are at 90 degrees to one another. To make a triangle you just need one more line slapped in there somewhere. If you start that third line at the middle of the circle (O) and draw it out to cross the tangent line at some random place (Q), it becomes pretty clear that the place it crosses the tangent line will be farther away when the angle (X) is bigger between this third line and that other line to the middle of the circle. The relationship between the angle and the distance out the touching line is called the tangent function.
But enough of that. I’ve put a simple diagram on the blog too if you can’t follow my logic.

The point is that a tangent touches once and then goes away and that’s why, when I’m telling stories that seem to have nothing to do with etymology, I’m off on a tangent.
The first guy to use this mathematical word with a rhetorical meaning was that famous Scottish poet Robbie Burns. The mathematical meaning appeared first in 1583 in Latin and before the century was out was popping up as if the word was English, which of course is what makes a word English. About 200 years later Robbie Burns used the now English word—not in one of his poems that are written with such a heavy Scottish brogue that they’re sometimes hard to read—but instead in a letter to a friend which is written in refreshingly understandable English.
That’s what I was getting at when I brought up Britney Spears and how people have more sides to them than we often realize. I was happy to see that Burns didn’t always write in such an impenetrable way. Maybe he was a closet math geek if he was the first one to use tangent with a non-mathematical meaning.
But imagine my shock and horror when I learned that one of his favourite things to write in letters to his friends was dirty poetry. I guess like Britney Spears there are some sides of some people that I’d just rather not know.


